Eyeglass lens processing apparatus

ABSTRACT

An eyeglass lens processing apparatus includes: a hole forming portion that includes a hole forming tool which forms a hole for attaching a rimless frame in an eyeglass lens; and breakage detector that detects whether or not the hole forming tool is broken.

TECHNICAL FIELD

The present invention relates to an eyeglass lens processing apparatuswhich forms a hole for attaching a rimless frame in an eyeglass lens.

BACKGROUND ART

A process of forming a hole for attaching a rimless frame, such as aso-called two point frame in an eyeglass lens, has been carried outmanually by means of a drilling machine and the like. In recent years,however, an eyeglass lens processing apparatus which carries out theprocess automatically has been proposed (refer to U.S. Pat. No.6,790,124 (JP-A-2003-145328)).

DISCLOSURE OF THE INVENTION Problems that the Invention is to Solve

In the processing apparatus, in view of the inner diameter of the holeto be formed in the eyeglass lens a hole forming tool such as, a finedrill, end mill, having a diameter in the order of 1 mm, is used. As aresult, in a case in which a large quantity of lenses is consecutivelyprocessed at a processing center and the like, it can happen that thehole forming tool breaks partway through the consecutive processing. Inthe event that processing is continued without this being noticed, alarge number of defectively processed lenses occur.

In view of the problem related to the related art, a technical problemwhich the invention is to solve is to provide an eyeglass lensprocessing apparatus which is capable of suppressing the occurrence of adefectively processed lens due to a breakage of a hole forming tool.

Means for Solving the Problem

In order to solve the aforementioned problem, the invention ischaracterized by including the following configuration.

(1) An eyeglass lens processing apparatus comprising:

a hole forming portion that includes a hole forming tool which forms ahole for attaching a rimless frame in an eyeglass lens; and

a breakage detector that detects whether or not the hole forming tool isbroken.

(2) The eyeglass lens processing apparatus according to (1), wherein thebreakage detector includes:

a contact;

a sensor that detects movement of the contact; and a movement mechanismportion that moves the hole forming tool relatively to the contact sothat the contact and a tip of the hole forming tool come into contact.

(3) The eyeglass lens processing apparatus according to (2) wherein thesensor is disposed outside a processing chamber in which the holeforming tool is disposed.

(4) The eyeglass lens processing apparatus according to (1) wherein thebreakage detector includes a sensor that detects whether or not a tip ofthe hole forming tool exists via non-contact.

(5) The eyeglass lens processing apparatus according to (4) wherein thesensor is disposed outside a processing chamber in which the holeforming tool is disposed.

(6) The eyeglass lens processing apparatus according to (1) furthercomprising:

a periphery processing portion that includes a periphery processing toolwhich grinds or cuts a periphery of the lens; and

a controller that operates in order the periphery processing portion andthe hole forming portion with respect to the lens, operates the breakagedetector before or after every forming of the hole, and, in the eventthat breakage of the hole forming tool is detected, prohibits subsequentoperation of the periphery processing portion and the hole formingportion.

(7) An eyeglass lens processing apparatus according to (6), furthercomprising a lens conveying portion that conveys the lens between theperiphery processing portion and the hole forming portion,

wherein when breakage of the hole forming tool is detected, thecontroller prohibits the subsequent operation of the lens conveyingportion.

(8) An eyeglass lens processing apparatus according to (6), furthercomprising an alarm,

wherein when the breakage of the hole forming tool is detected, thecontroller causes the alarm to issue warning to that effect.

ADVANTAGE OF THE INVENTION

According to the invention, it is possible to suppress the occurrence ofa defectively processed lens due to a breakage of a hole forming tool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of an eyeglass lensprocessing system which is an embodiment of the invention;

FIG. 2 is a schematic configuration view of a periphery processingapparatus;

FIG. 3 is a schematic configuration diagram of a lens holding mechanismof a hole forming apparatus;

FIG. 4 is a schematic configuration diagram of a vertical and left-rightmovement mechanism of the hole forming apparatus;

FIG. 5 is an external view showing a schematic configuration of a holeforming portion;

FIG. 6 is a sectional view showing a schematic configuration of the holeforming portion;

FIG. 7 is a schematic configuration diagram of a drill breakagedetector;

FIG. 8 is a schematic block diagram of a control system of the eyeglasslens processing system;

FIG. 9 is a diagram illustrating a forming of a hole in a lens; and

FIG. 10 is a schematic configuration diagram of a modified example ofthe drill breakage detector.

BEST MODE FOR CARRYING OUT THE INVENTION

An embodiment of the invention will hereafter be described withreference to the drawings. FIG. 1 is a schematic configuration diagramof an eyeglass lens processing system which is an embodiment of theinvention.

An eyeglass lens processing system 1 includes: a periphery processingapparatus 100 for grinding or cutting (grinds in the case of theembodiment) the periphery of an eyeglass lens LE; a lens conveyingapparatus 200 (robot hand apparatus) for conveying the lens LE; a holeforming apparatus 300 for forming a hole in the lens LE; a lens stockingapparatus 400 for stocking a plurality of lens storage trays 401, inwhich the lenses LE for both the right and left eye are stored as apair; and a system controller 600 for controlling each apparatus. Thesystem controller 600 is connected to a host computer (host PC) 620 formanaging an ordering data. A warning lamp 610, which is connected to thesystem controller 600, gives a warning in the event of an abnormality ineach apparatus, such as a breakage in a hole forming tool.

The stocking apparatus 400 includes: a transfer stage 410 and areceiving stage 420, onto which the trays 401 are loaded in series in avertical direction (z direction); a movement mechanism part 412 formoving the stage 410 in the vertical direction; a movement mechanismportion 422 for moving the stage 420 in the vertical direction; a clamparm 430 for clamping the tray 401 and moving it from the stage 410 tothe stage 420; and a barcode reader 440 for reading a barcode of a workNo. assigned to the tray 401. 10 trays 401 can be loaded onto each stage410 and 420, and 10 pairs of the lens LE can be processed consecutively.

The periphery processing apparatus 100 and the hole forming apparatus300 are installed on a table 20 of the system 1. The conveying apparatus200 is installed so as to be movable in a left-right direction (Xdirection) along a conveying path provided between the peripheryprocessing apparatus 100 and hole forming apparatus 300 and the stockingapparatus 400. The conveying apparatus 200 is provided with a verticalslide 214 so as to be movable in the vertical direction, the verticalslide 214 is provided with a first arm 216 so as to be rotatable in ahorizontal direction, and the first arm 216 is provided with a secondarm 218 so as to be rotatable in the horizontal direction. A tip of thesecond arm 218 is provided with a sucking member 222 that sucks andholds the lens LE. The sucking member 222 is connected to an air pump,whereby it sucks and holds the lens LE by means of the air pump drive.The conveying apparatus 200 takes out an unprocessed lens LE from thetray 401, conveys it in turn to the periphery processing apparatus 100and the hole forming apparatus 300, then returns the processed lens LEto the same (original) tray 401.

FIG. 2 is a schematic configuration view of the periphery processingapparatus 100. The lens LE is clamped by chuck shafts 111 and 112 whichextend in the vertical direction. The upper side chuck shaft 111 ismoved in the vertical direction by a movement mechanism portion 110provided in the center of a sub-base 102, and is rotated by a motor 115.The lower side chuck shaft 112 is rotatably held by a holder 120, whichis fixed to a main base 101, and is rotated in synchronization with thechuck shaft 111 by a motor 123.

To clamp the lens LE by the chuck shafts 111 and 112, a cup 390 as aprocessing jig is attached to the lens LE by an adhesive pad. A cupholder 113 is attached to an upper tip of the chuck shaft 112 for thepurpose of inserting a base of the cup 390. A lens retainer 114 isattached to a lower tip of the chuck shaft 111.

The lens LE which is clamped by the chuck shafts 111 and 112 is grindedfrom two directions by periphery processing portions 150R and 150Lhaving rotating shafts to which grindstones 151 are attachedrespectively. The grindstone 151 includes a grindstone for roughing, agrindstone for plane-finish, a grindstone for bevel-finishing, and agrindstone for chamfering. The periphery processing portions 150R and150L are bilaterally symmetrical, and are respectively moved in thevertical direction and the right-left direction by the movementmechanism portion provided on the sub-base 102. A lens shape measuringportion 160 is contained in a central rear side of the sub-base 102. Theconfiguration of the periphery processing apparatus 100 is basically thesame as one in U.S. Pat. No. 5,716,256 (JP-A-9-253999).

Next, a description of a configuration of the hole forming apparatus 300will be given with reference to FIGS. 3 to 7. FIG. 3 is a schematicconfiguration diagram of a lens holding mechanism of the hole formingapparatus 300, in which the inside of the apparatus 300 is viewed fromthe front. The lens LE is clamped by chuck shafts 311 and 321 whichextend in the vertical direction. The upper side chuck shaft 321 isrotatably held by a holder 322, and is rotated by a motor 323 providedon the top of the holder 322. A block 330 is fixed to the upper part ofa sub-base 302, which stands on a main base 301, and the holder 322 isattached to the front side of the block 330 so as to be movable in thevertical direction along a slide rail 331. The holder 322 is moved inthe vertical direction by a motor 333 provided on the top of the block330. With this arrangement, the chuck shaft 321 is moved in the verticaldirection. The lower side chuck shaft 311 is rotatably held by a holder312 fixed to the main base 301, and is rotated in synchronization withthe chuck shaft 321 by a motor 315.

A cup holder 313 is attached to an upper tip of the chuck shaft 311 forthe purpose of inserting the base of the cup 390 fixed to the lens LE. Alens retainer 325 is attached to a lower tip of the chuck shaft 321.

A hole forming portion 800 is moved in the vertical direction and theleft-right direction by a movement mechanism portion 350. FIG. 4 is aschematic configuration diagram of a vertical and left-right movementmechanism of the hole forming apparatus 300, in which the inside of theapparatus 300 is viewed from the rear. Two shafts 351 which extend inthe vertical direction are stood on the main base 301, and a movementsupport base 353 is provided in such a way as to be movable in thevertical direction along shafts 351. A block 355 is fixed to the upperpart of the sub-base 302, and a feed screw 359 extending in the verticaldirection is coupled to a rotating shaft of a motor 357 provided on thetop of the block 355. A nut block 360 is fixed to the rear of themovement support base 353, and the movement support base 353 is moved inthe vertical direction, in conjunction with the nut block 360, by therotation of the feed screw 359.

A feed screw 365 extending in the left-right direction is coupled to arotating shaft of a motor 363 fixed to the movement support base 353.When the feed screw 365 rotates, a movement block 370 formed with a feednut is moved in the left-right direction, and is guided by a shaft 369extending in the left-right direction. The hole forming portion 800 isattached to the movement block 370 via an attachment plate 373. As aresult, the hole forming portion 800 is moved in the vertical directionby a forward/reverse rotation of the motor 357, and moved in theleft-right direction by a forward/reverse rotation of the motor 363.

FIG. 5 is an external view showing a schematic configuration of the holeforming portion 800, and FIG. 6 is a sectional view showing a schematicconfiguration of the hole forming portion 800.

A fixing plate 801 as a base of the hole forming portion 800 is fixed tothe attachment plate 373 of the movement mechanism portion 350. A rail802 extending in a forward-back direction (Y direction) is attached tothe fixing plate 801, and a slider 803 is provided so as to be slidablealong the rail 802. A movement support base 804 is fixed to the slider803, and the movement support base 804 is moved in the forward-backdirection by rotating a ball screw 806 by a motor 805 fixed to thefixing plate 801.

A rotation support base 810 is rotatably pivoted to the movement supportbase 804 by means of a bearing 811. A gear 813 is fixed to the rotationsupport base 810 on one side of the bearing 811. The gear 813 isconnected, via an idle gear 814, to a gear 815 attached to a rotatingshaft of a motor 816 which is fixed to the movement support base 804.That is, the rotation support base 810 is rotated around an axis of thebearing 811 by means of the motor 816.

A rotation portion 830 for holding a tool for forming a hole andgrooving is provided on the tip of the rotation support base 810. Therotation portion 830 is moved in the forward-back direction by the motor805. A pulley 832 is attached to a central part of a rotating shaft 831of the rotation portion 830, and the rotating shaft 831 is rotatablypivoted by two bearings 834. A drill 835, which acts as a hole formingtool, is attached to one end of the rotating shaft 831 by a chuck 837,while a spacer 838 and a grooving grindstone 836 are attached to theother end by a nut 839. A diameter of the drill 835 is in the order of0.8 mm.

A motor 840 for rotating the rotating shaft 831 is fixed to anattachment plate 841 attached to the rotation support base 810. A pulley843 is attached to a rotating shaft of the motor 840. A belt 833 iswound around the pulley 832 and the pulley 843 inside the rotationsupport base 810, and the rotation of the motor 840 is transmitted tothe rotating shaft 831.

FIG. 7 is a schematic configuration diagram of a drill breakage detector850. A shaft 853 is held, via a sliding bearing 852, by a support base851 of the drill breakage detector 850, in such a way as to be movablein the vertical direction. A bottom surface 853 a of the shaft 853projects beyond the support base 851, thereby forming a contact withwhich the drill 835 is contacted. The shaft 853 is constantly urged in adownward direction by a spring 854. A micro switch 855 provided on thetop of the support base 851 is disposed in such a way as to be switchedon (energized) by a top end 853 b of the shaft 853 being pushed by acertain amount in an upward direction. That is, in a case in which thedrill 835 is not broken, when the rotation portion 830 disposed in aprescribed initial position is moved by a certain amount in the upwarddirection, a tip of the drill 835 comes into contact with the bottomsurface 853 a of the shaft 853, thereby pushing up the shaft 853. Alength of the drill 835 is known, and when the shaft 853 is moved by acertain amount in the upward direction, the micro switch 855 comes on.By this means it can be detected that the drill 835 is not broken. It isacceptable to use a photodetector such as a light extinction sensor, inplace of the micro switch 855, as a detector which detects the movementof the shaft 853.

The support base 851 is provided on top of a partition 305 which forms aprocessing chamber 303 of the hole forming apparatus 300. Although thebottom surface 853 a of the shaft 853 is inside the processing chamber303, the top end 853 b of the shaft 853 and the micro switch 855, whichacts as an electrical element, are disposed outside the processingchamber 303. Inside the processing chamber 303, when forming a hole inthe lens LE, air supplied by a not-shown air pump is blown out of anozzle 307, whereby shavings (processing waste) adhering to the lens LEare blown away. When forming a groove in the lens LE, water is sprayedfrom a nozzle 308. As a result, shavings and water fly around inside theprocessing chamber 303. As it is necessary to protect the micro switch855, which is the electrical element, from the shavings and water, it isdisposed outside the processing chamber 303.

Next, an operation of the eyeglass lens processing system which has thiskind of configuration will be described, using a schematic block diagramof a control system in FIG. 8. As a preparation for processing, anoperator stores one pair of unprocessed lenses LE in the tray 401, andloads ten trays 401 onto the stage 410 of the stocking apparatus 400 inseries in the vertical direction. The cup 390 is fixed in advance to thelens LE which is stored in the tray 401. The operator starts theprocessing system by pressing a processing switch of the systemcontroller 600.

First, the stocking apparatus 400 starts operating and the bar codereader 440 reads the work No. assigned to the tray 401 which is on thetop level. The system controller 600 reads a target lens shape data,hole position data, hole direction data and the like, which correspondsto the work No., from the host PC 620, then sends the data necessary forthe respective process to the periphery processing apparatus 100 and thehole forming apparatus 300. When the tray 401 on the top level ispositioned in a prescribed delivery position, the conveying apparatus200 sucks and holds the lens LED via the sucking member 222, and conveysit to the periphery processing apparatus 100. In the peripheryprocessing apparatus 100, the lens LE is clamped by the chuck shafts 111and 112, and a configuration of a front surface and a rear surface ofthe lens LE is measured by the operation of the lens shape measuringportion 160. When a hole is formed, the lens shape measuring portion 160measures the hole position (a position in the Z direction) of the frontsurface of the lens LE in accordance with the hole position data (forexample, a radial angle θ and a radial length d in respect to the centerof the lens chuck). A measurement result of the hole position is sent tothe hole forming apparatus 300.

When the measurement result of the lens LE configuration is obtained,the periphery of the lens LE is grinded by the periphery processingportions 150R and 150L. Then, when the periphery processing is finished,the lens LE is taken out from the periphery processing apparatus 100 bythe conveying apparatus 200 and conveyed to the hole forming apparatus300. In the hole forming apparatus 300, when the lens LE is placed onthe chuck shaft 311, the motor 333 is driven by control of thecontroller 380, and the chuck shaft 321 is moved in the downwarddirection, thereby clamping the lens LE.

At the time of forming a hole, the controller 380 detects whether drillbreakage occurs or not by the drill breakage detector 850 before forminga hole. First, the controller 380 controls the drive of the motors 357and 363 of the movement mechanism portion 350, the motor 805 of the holeforming portion 800, and the like to place the drill 835 in the initialposition below the bottom surface 853 a of the shaft 853 and then tomove the drill 835 by a certain amount in the upward direction by thedrive of the motor 357 as shown in FIG. 7. If the tip of the drill 835comes into contact with the bottom surface 853 a of the shaft 853 andthe micro switch 855 turns on due to the shaft 853 being pushed upwards,it is detected that there is no drill breakage. In a case in which thecontroller 380 detect that there is no drill breakage based on an outputsignal from the micro switch 855, the process shifts to the hole formingstage.

A description will be given of the hole forming. The hole forming datais determined by the controller 380 based on the input data (holeposition data, hole direction data) from the host PC 620, and the lensLE front surface hole position data (Z direction position) obtained fromthe lens shape measuring portion 160 of the periphery processingapparatus 100. The controller 380 controls the drive of the motor 315and the motor 323 to rotate the lens LE which is clamped by the chuckshafts 311 and 321, and controls the drive of the motors 357, 363 and805 and the like to position the tip of the drill 835 in hole positionP1 of the lens LE, as shown in FIG. 9. In a case of having the holedirection data of an angle α1 in the X-Z directions, the controller 380controls the drive of the motor 816 to tilt the drill 835 by the angleα1. In this condition, by controlling each motor of the movementmechanism portion 350 in such a way that the tip of the drill 835advances in the direction of the angle α1 while the drill 835 is beingrotated, a hole is formed in the lens LE. In a case of having an angledata related to the X-Z directions, the hole forming can be carried outby controlling the rotation angle of the lens LE (refer to U.S. Pat. No.6,790,124 (JP-A-2003-145328) for details). When forming a hole, air isejected from the nozzle 307, whereby the shavings adhering to the drill835 and the hole in the lens LE are blown away.

When the hole forming is finished, the lens LE is taken out from thehole forming apparatus 300 by the conveying apparatus 200, and returnedto its original position in the same (original) tray 401. Subsequently,the other lens LE which is in the same tray 401 is conveyed in the sameway, and periphery processing is carried out by the periphery processingapparatus 100 and hole forming is carried out by the hole formingapparatus 300. When the processing of the pair of lenses LE stored inthe tray 401 is finished, the tray 401 containing the processed lens LEis moved to the stage 420 by the clamp arm 430, and loaded thereon.Subsequently, to process the lens LE contained in the next tray 401, thetray 401 on the second level is moved to the prescribed deliveryposition, and the lens LE contained in the tray 401 is conveyed to theperiphery processing apparatus 100 and the hole forming apparatus 300 bythe conveying apparatus 200, and processing is carried out in the sameway. In a case in which processing includes grooving processing, thegrooving processing is carried out by the grooving grindstone 836 whichis included in the hole forming portion 800 of the hole formingapparatus 300.

In this way, a plurality of the lenses LE contained in the tray 401 isprocessed consecutively. During this time, the operator can carry outoperating preparation of another system, as it is not necessary toconstantly attend the processing system.

As the drill 835 has a small diameter of 0.8 mm, it tends to break inthe course of processing a large quantity of the lenses LE. As theconfiguration of the drill 835 is such as to have a uniform diameterfrom the base to the tip, it breaks from the base. To detect whetherdrill breakage occurs or not by the drill breakage detector 850 everytime before forming a hole, the controller 380 moves the drill 835 by acertain amount in the upward direction by the drive of the motor 357after placing the drill 835 in the initial position below the bottomsurface 853 a of the shaft 853. In a case of drill breakage occurringduring the previous processing, since the shaft 853 cannot be pushedupwards even by moving the drill 835 by a certain amount in the upwarddirection, the micro switch 855 does not turn on. In a case that thereis no on signal (energization signal) from the micro switch 855 when thedrill 835 is moved in the upward direction, the controller 380determines that the drill 835 is broken. In a case in which thecontroller 830 detects that the drill 835 is broken, the subsequentprocessing is prohibited (stopped) and an error message to that resultis displayed on an indicator 381 provided on the front surface of thehole forming apparatus 300. Further, the controller 380 sends to thesystem controller 600 an error signal to the effect that the drill hasbroken. The system controller 600 illuminates the warning lamp 610 towarn the operator of a system abnormality, and prohibits (stops) theoperation of the periphery processing apparatus 100 and the conveyingapparatus 200. The operator can be informed of the drill breakage by theillumination of the warning lamp 610 and the error message of theindicator 381, and is therefore able to replace the drill 835. By thismeans, it is possible to suppress the occurrence of a large quantity ofdefectively processed lenses due to drill breakage. It is alsoacceptable to operate the drill breakage detector 850 after forming thehole rather than before forming the hole.

Various modifications are possible in the embodiment describedheretofore. For example, with regard to the drill breakage detector 850shown in FIG. 7, although the configuration is such that the drill 835is moved in the upward direction by the movement mechanism portion 350,thereby pushing up the shaft 853, it is also acceptable to relativelyreverse the movement. That is, it is also acceptable to provide amechanism which moves the drill breakage detector 850 to a position inwhich it comes into contact with the tip of the drill 835, so that themicro switch 855 turns on in the same way when there is no drillbreakage.

Furthermore, it is also possible to carry out drill breakage detectionby using a detector which detects whether the tip of the drill 835occurs via non-contact. For example, as shown in FIG. 10, a capacitancesensor 860 is positioned outside the processing chamber 303, and the tipof the drill 835 is brought into proximity with the capacitance sensor860 when detecting drill breakage. In the event that the drill 835 isbroken, the tip does not come into proximity with the capacitance sensor860, and thus the controller 380 is able to detect whether a drillbreakage occurs or not from a difference in an output signal from thecapacitance sensor 860.

In the embodiment, the configuration is such that the hole formingportion 800 and the drill breakage detector 850 are provided separatelyfrom the periphery processing portions 150R and 150L, but aconfiguration in which they are all provided in the periphery processingapparatus 100, as in U.S. Pat. No. 6,790,124 (JP-A-2003-145328), is alsoacceptable. Furthermore, it is also acceptable that the peripheryprocessing portion is one which grinds the lens LE from one direction,rather than from two directions. Further still, it is also acceptable touse a conveyor belt type as a configuration which consecutively feedsthe lens LE contained in the tray 401.

1. An eyeglass lens processing apparatus comprising: a lens holding unitthat holds and rotates an eyeglass lens; a hole forming tool which formsa hole for attaching a rimless frame in a refractive surface of thelens; a tilt mechanism portion that tilts the hole forming toolrelatively to the lens held by the lens holding unit; a movementmechanism portion that moves the hole forming tool in a rotating axisdirection thereof relatively to the lens held by the lens holding unit;a calculator that calculates hole forming data based on target lensshape data, hole position data and hole direction data of the rimlessframe; a breakage detector that is provided outside a partition forminga lens processing chamber and includes a sensor for detecting movementof a shaft due to an abutment against a tip of the hole forming tool ordetecting a proximity state of the tip of the hole forming tool; and acontroller that judges whether or not the hole forming tool is brokenbased on an output of the breakage detector and prohibits the holeforming based on the hole forming data when the hole forming tool isbroken.
 2. The eyeglass lens processing apparatus according to claim 1,further comprising: a periphery processing tool which grinds or cuts aperiphery of the lens, where the controller in the event that the holeforming tool is broken, prohibits the periphery processing and the holeforming.
 3. An eyeglass lens processing apparatus according to claim 2,further comprising a lens conveying portion that conveys the lensbetween the periphery processing portion and the hole forming portion,wherein when the hole forming tool is broken, the controller prohibitsthe operation of the lens conveying portion.
 4. An eyeglass lensprocessing apparatus according to claim 2, further comprising an alarm,wherein when the hole forming tool is broken, the controller causes thealarm to issue warning to that effect.